Radiance 10/100Mbps Interface Line Cards 9
Link Loss Return Switch (LLR)
The 10/100Mbps interface line card incorporates Link Loss Return
(LLR) functionality as an aid in troubleshooting remote connections on
its fiber optic ports. When LLR is enabled, the loss of inbound link
pulses on a port stops the transmission of outbound link pulses on the
same port. For example, if LLR is enabled on port 2 and its receiver
(RX) stops detecting link pulses, then port 2’s transmitter (TX) will
stop sending link pulses. LLR is enabled on each fiber port indepen-
dently. LLR is not applicable to copper ports.
Link Loss Return is enabled on Port 1 when switch LLR1 is UP, and it
is enabled on Port 2 when switch LLR2 is UP. The unit is shipped with
LLR disabled on both ports. Refer to
Link Loss Return
in the User
Guide section of this manual for more detailed information.
Link Loss Carry Forward Switch (LLCF)
In addition to LLR, the R612-51 and R642-xx units support Link Loss
Carry Forward functionality to help with troubleshooting remote
connections.
Unlike LLR, which only applies to fiber ports, LLCF affects both ports
on the card. When LLCF is enabled, the loss of inbound link pulses on
a port stops the transmission of outbound link pulses on the opposite
port. For example, if LLCF is enabled, the loss of incoming link pulses
at Port 1 stops the transmission of link pulses out of Port 2. Con-
versely, if Port 2 stops receiving link pulses, Port 1 will not transmit
link pulses.
Link Loss Carry Forward is enabled on both ports when switch LLCF
is UP. The unit is shipped with LLCF disabled. Refer to
Link Loss
Carry Forward
in the User Guide section of this manual for further
details.
